MODULATION OF PREY-CAPTURE BEHAVIOR IN PLETHODON-CINEREUS (GREEN) (AMPHIBIA, CAUDATA)

Many feeding kinematic studies do not identify sources of mechanical v ariation related to the type or size of prey. Studies of salamanders h ave concentrated on determining the morphological basis of feeding mec hanics or on phylogenetic comparisons; few have examined variability w ithin a species. A series of feeding trials was designed to test wheth er Plethodon cinereus of different age/size classes exhibits stereotyp ic patterns in capturing prey of differing type and size. Stopframe vi deo analyses of feedings were made using 19 salamanders of varying bod y size and four prey types chosen to resemble items in the natural die t of the species. Five morphological features of each salamander, leng th and width of prey items, and 15 kinematic variables were used to de scribe each feeding trial. Statistical analyses of kinematic and morph ological variables show that the feeding behavior of this species vari es significantly with prey type. Effects of salamander size and prey s ize within prey types were a source of variation in some kinematic var iables; among-individual variation partitioned with salamander body si ze. Different feeding modes resulted from distinctive combinations of distances from prey, amount of tongue protrusion, body movements, and duration of mouth closure, which varied with the use of jaw prehension and lingual prey capture. Presence of a repertoire of behaviors, comp osed of versatile combinations of movements, suggests that Plethodon c inereus modulates feeding mechanics to capture different types of prey . Consideration of natural prey in experiments, and of prey type in co mparisons made across taxa, are necessary to investigations of the evo lution of feeding behaviors. (C) 1995 Wiley-Liss, Inc.